I ran into a few questions about settings migration on forums and elsewhere, so I thought a blog post might help. Here are two key considerations to keep in mind:

Sync Settings synchronizes settings between installations of the same major version of Photoshop. For example, settings are synchronized between a Photoshop CC 14.1 installation and a Photoshop CC version 14.2 installation.

Sync Settings does not synchronize settings across installations of different Photoshop major versions. For example, Photoshop CC version 14.1 settings are not synchronized with an installation of the 2014 release of Photoshop CC (technically, version 15.0).

If you want to migrate presets/settings from one major version of Photoshop to another, you can do so in one of the following two ways:

When you first launch the newer version of Photoshop, you are prompted to migrate the presets/settings. Choose Yes.

At any point in time, select Edit > Presets > Migrate Presets to migrate settings.

Also note that the main preference file is not migrated as part of presets migration.